Coastal Caisson: Sustainability Fuels Construction Of New Basements In Florida

How does cutting your electricity bill in half sound? How about eliminating your water bill? Think it's impossible? Think again. Odessa-based foundation company Coastal Caisson has the solutions.

At a time when most construction-based companies are still waiting for the housing market to recover, Coastal -- owned by German foundation giant Bauer -- has found its niche by focusing on a growing concern in the construction business: sustainability.

Using geothermal chillers to keep fish tanks cool at Mote Marine Laboratory in Sarasota, utilizing thermal ice storage to cool an office building, and employing geothermal technology to help reduce water consumption from strawberry farmers are just a few of the ideas on the table.

Perhaps the development that's garnered the most attention, though, is the construction of water-tight basements in Florida. The project has drawn its fair share of skeptics, which is understandable given that Florida has one of the highest water tables in the country.

"The most common response from people is, 'A basement in Florida -- are you kidding?'" says Tom Mudano, owner representative and project manager. But a trip to Coastal's sprawling complex, recently relocated form Clearwater, should silence any naysayers. Sitting along the right side of Byrd Legg Drive is a 3,000-square-foot building that could easily be mistaken for a one-level residence from the outside. Take a walk inside, though, and you'd find yourself in a series of offices sitting atop a showroom located 30 feet below the ground.

More than 300 people have visited the site since construction started last year after President and CEO Charles Puccini grew tired of hearing the project couldn't be done.

"By far the biggest challenge is breaking the 'That's not how we do it!' mentality," he says. "These are solvable problems -- you just have to engineer for them."

As of May, Coastal Caisson's basement building proposal has been accepted in Pasco and Hernando counties, where Puccini claims the roads and neighborhoods are ready to go when people decide to move in.

"We want to be positioned with an acceptable product and showpiece when the housing market returns," he says. "And I think we'll be there."

But Puccini admits he wasn't always so concerned with innovative and environmentally conscientious construction.

"When the economy was good we just didn't care," he says. "Then the money stopped flowing and people started thinking they shouldn't be burning so much gas."

Adversity Spawns Creativity

The collapse of the housing market was a rude awakening with a silver lining for the construction industry: There was no longer an excuse to ignore creative thinking.

So Puccini put on his thinking cap. His love for traveling led him to the canals of Venice, where he drew inspiration for an ambitious research project that has finally come to fruition.

The process of building a basement begins with a machine dubbed a Cutter Soil Mixture -- developed by Bauer in 2004 -- to mill the earth, separate the rock and inject a concrete slurry into the soil. The machine forms a series of 8 foot panels, which can be made up to 48 inches thick and 100 feet deep, that eventually form a seamless, monolithic wall. Following a 28-day curing process, the site is excavated, floors are poured and the interior walls of the basement are water-proofed.

Now that you know how it's done, you may be wondering why anyone would want a basement in Florida. The answer is simple -- energy efficiency.

A typical 3,000-square-foot building uses 6 tons of HVAC. A one-story building with a basement and a geothermal air conditioning unit will use 3 tons on top and 3/4 of a ton below, effectively reducing your energy consumption and bill by up to 50 percent, according to Coastal's research.

Gray Mullins, a professor in the Department of Civil & Environmental Engineering at the University of South Florida, was tapped by Coastal to lead a one-year study of the geothermal aspect to their basement project: using the temperature of the ground to heat and cool the building.

"Geothermal systems have been out there for a couple of decades, but homeowners weren't willing to spend up to triple the cost [of a typical air conditioning unit] to recoup long term on lower utility bills," Mullins says. He also cites that because home purchases, compared to automobiles and computers, are intended to last for 30-40 years for the average buyer, it often correlates to slower progress in areas of home energy reduction.

"Now we have homes that are better insulated, more energy efficient air conditioning systems, and geothermal technology," Mullins says. "Put all those things together and you have a huge capability to reduce carbon footprint."

Seeing Endless Opportunities

Building below ground also opens up an endless amount of opportunities for commercial properties, including a possible solution to a notorious flood problem in Tarpon Springs.

Traditionally, box culverts would be set in the ground to act as a pipeline for the water, according to Mudano. But he says Coastal has a more economical alternative using the same concept from CSM. Following the installation of two walls, dirt would be excavated, a floor installed and a lid placed on top covered by dirt.

"It would save Pinellas County $7 million to go with this approach," Mundano says.

Coastal's technology also caught the attention of the Jacksonville District of the Corps of Engineers, which enlisted Coastal to work on the Herbert Hoover Dike Rehabilitation Project in 2007. The project is intended to last for 10 years -- with additional contracts (around 50 by the end of the project, according to Puccini) issued for every three miles of completion. In May, the company was awarded a second contract of $40 million to continue work on reducing the flood risk.

After two hurricanes hit the lake in the late 1920s -- including Hurricane Okeechobee, which was responsible for 2,500 deaths, according to a 1997 National Weather Service study -- the U.S Army Corps of Engineers built the Herbert Hoover Dike. The dike performed its duty, but 70 years of water spilling over and soaking into the ground has caused piping, creating channels for water to leak through.

Coastal's responsibility is to use its CSM technology to create a wall 80 feet deep that forces water leaking out to go underneath the structure and back up to the surface, significantly slowing the flow of water.

Now that Coastal has figured out how to cut off the water table, they've utilized their underground construction methods to build vertical water reuse ponds that go up to 100 feet deep into the ground.

"We use about 120-160 million gallons of water a day in the Tampa Bay area," says Puccini, "and we dump about 80 million gallons back into the (Tampa) Bay every day instead of catching it and using it."

Coastal is hoping to take it a step farther in the future by capturing the rainwater that falls from the roofs of homes and piping to a central reuse pond with the purpose of irrigating the entire neighborhood. Those kinds of creative ideas seem to be abundant these days, according to Puccini, who once again credits the economy for a boom in innovative thinking.

"I'm getting approached by people with all kinds of ideas because they finally have time to stop and think."

Matt Spencer, a University of South Florida grad, is a native Floridian who enjoys sharing his love for Patty Griffin, browsing produce stands, spending hours in record shops and gawking at the ice cream selection in grocery stores. Comments? Contact 83 Degrees.